1. Field of the Invention
The present invention relates to a propulsion unit for a wheelchair, and more particularly to a propulsion unit mounted on a track for a wheelchair wheel.
2. Description of the Prior Art
Many older people develop physical handicaps at a late stage in their lives requiring that they adapt themselves to the confines of a wheelchair and learn how to propel and navigate the wheelchair. Manual wheelchairs are very difficult to propel as strength and dexterity are required to grasp and rotate the cold metal handrails.
Thus, it is common for wheelchair users of all ages to experience upper limb pain and pathology due to the requirements placed on the arms for wheelchair locomotion. As a result of greater than normal usage of the upper limbs, proper propulsion mechanics are paramount in preventing injuries.
Several hand propulsion devices have been developed for conventional wheelchairs to increase the mechanical advantage and thereby reduce the force that such occupants must exert to propel a wheelchair. However, the relatively complicated manipulations required to operate the prior art devices deters from their use.
In most all prior art hand propulsion devices, the installation of such devices requires alterations to the wheelchair. Few if any prior art devices can be easily retrofitted to existing wheelchairs without the need for modifying the latter.
Furthermore, there are no prior art hand propulsion devices that offer the versatility of being compatible with wheelchairs of varying wheel diameters. In many prior art cases, the propulsion device is mounted to the axle of the wheelchair; and therefore must be available in different lengths as not all wheelchairs have wheels of the same diameter.
Therefore, there is a need for a propulsion device for wheelchairs that at least addresses some of the above-stated issues.